Method and apparatus for generating synchronization signal in internet of things

Abstract

A method and an apparatus for generating a synchronization signal in the Internet of things. In the method for generating a synchronization signal, subcarrier mapping may be performed by exchanging a signal allocated to an upper subcarrier group and a signal allocated to a lower subcarrier group among all subcarriers allocated for the synchronization signal with each other, in an in-band operation mode or a guard band operation mode of the Internet of things.

What is claimed is: 
     
       1. A method for generating a synchronization signal, in the Internet of things by a transmitting apparatus, comprising:
 in an in-band operation mode or a guard band operation mode of the Internet of things, 
 dividing all subcarriers allocated for the synchronization signal into a first upper subcarrier group and a first lower subcarrier group; and 
 performing a first subcarrier mapping by exchanging a signal allocated to the first upper subcarrier group and a signal allocated to the first lower subcarrier group with each other, and 
 in a standalone operation mode of the Internet of things, 
 dividing all subcarriers allocated for the synchronization signal into a second upper subcarrier group and a second lower subcarrier group; and 
 performing a second subcarrier mapping without exchanging the second upper subcarrier group and the second lower subcarrier group with each other. 
 
     
     
       2. The method of  claim 1 , further comprising:
 performing subcarrier indexing on a signal on which the first subcarrier mapping is performed; 
 performing inverse fast Fourier transform (IFFT) on the signal on which the subcarrier indexing is performed; and 
 inserting a cyclic prefix (CP) into the signal on which the IFFT is performed. 
 
     
     
       3. The method, of  claim 1 , further comprising:
 performing subcarrier indexing on a signal on which the second subcarrier mapping is performed; 
 performing IFFT on the signal on which the subcarrier indexing is performed; and 
 inserting a CP into the signal on which the IFFT is performed. 
 
     
     
       4. The method of  claim 1 , wherein the second upper subcarrier group is included in a physically negative subcarrier group, and the second lower subcarrier group is included in a physically positive subcarrier group. 
     
     
       5. The method of  claim 1 , wherein the first upper subcarrier group and the first lower subcarrier group are included in a physically negative subcarrier group. 
     
     
       6. The method of  claim 1 , wherein in the case in which a total number of all subcarriers is 12, indices for the first upper subcarrier group and the second upper subcarrier group are −1, 0, 1, 2, 3, and 4, respectively, and indices for the first lower subcarrier group and the second lower subcarrier group are 5, 6, 7, 8, 9, and 10, respectively. 
     
     
       7. The method of  claim 1 , further comprising deciding whether or not an operation mode for the Internet of things is the standalone operation mode or the in-band operation mode/the guard band operation mode. 
     
     
       8. A transmitting apparatus transmitting a synchronization signal in the Internet of things, comprising:
 a processor performing a first subcarrier mapping by exchanging a first upper subcarrier group and, a first lower subcarrier group among all subcarriers allocated for the synchronization signal with each other to generate the synchronization signal, in an in-band operation mode or a guard band operation mode of the Internet of things; and 
 a radio frequency (RF) module transmitting the generated synchronization signal, 
 wherein the processor performs a second subcarrier mapping without exchanging a second upper subcarrier group and a second lower subcarrier group among all subcarriers allocated for the synchronization signal with each other to generate the synchronization signal, in a standalone operation mode of the Internet of things. 
 
     
     
       9. The transmitting apparatus of  claim 8 , wherein the processor performs subcarrier indexing on a signal on which the first subcarrier mapping is performed, performs inverse fast Fourier transform (IFFT) on the signal on which the subcarrier indexing is performed, and inserts a cyclic prefix (CP) into the signal on which the IFFT is performed. 
     
     
       10. The transmitting apparatus of  claim 8 , wherein the second upper subcarrier group is included in a physically negative subcarrier group, and the second lower subcarrier group is included in a physically positive subcarrier group. 
     
     
       11. The transmitting apparatus of  claim 8 , wherein the first upper subcarrier group and the first lower subcarrier group are included in a physically negative subcarrier group.